Can't say for sure without an example, but try these two solutions.

I. Under Tools-Options-Edit Tab
Make sure the "Fixed Decimal" is unchecked. This will change 260 to 2.6 and
2620 to 26.2.

II. Check the formatting. You might have a strange custom number format like
1234
this will make any number entered show up as 1234 instead of the number.
Change it to General or Number or something more appropriate.

"CJ" wrote:

I'm entering an amount into a cell, but the screen shows a number altogether
different from what I type.

I checked the format of the cell. I couldn't see anything wrong.